Question

In lake test of ${Al^{3+}}$ ion, there is formation of coloured floating. It is due to :

• A. adsorption of litmus by $\ce{H2O}$
• B. adsorption of litmus by $\ce{Al(OH)3}$
• C. adsorption of litmus by $\ce{Al(OH)4^{-}}$ -
• D. none of these

Answer 1

Answer: (B)

adsorption of litmus by $\ce{Al(OH)3}$

Answer 2

In lake test of ${Al^{3+}}$, a coloured floating lake is formed as ${Al(OH)_3}$ which being a solid surface (suspension), adsorbs litmus colour, resulting in coloured floating lake appearance.